He unveiled the new Elekta 4 linear accelerator which is used by therapeutic radiographers to administer radiotherapy treatment.

Guy's and St Thomas' has five linear accelerators – one at Guy's, which is currently being replaced by a brand new machine, and four at St Thomas', which are all-new, state-of-the-art machines to ensure patients receive the very best treatment.

The new Elekta 4 linear accelerator has been installed at a cost of approximately £1 million, thanks to funding from the Department of Health.

Peter Moore, who has been a Town Crier for more than 25 years, is a familiar figure around London and especially in Southwark. Thousands of Londoners will also recognise his distinctive voice as a regular caller (Peter in Wandsworth) to LBC radio's Clive Bull.

Peter said: "I have received regular treatment at St Thomas' for the last 10 years and I am very grateful for the fantastic care that I have been given.

"Coming along to officially open this new piece of equipment was a small way of giving something back to the hospital for the wonderful treatment I have had – I am fed up with the NHS being knocked, my experience has been great and I will do anything I can to let people know about that."

Guy's and St Thomas' provides all radiotherapy services for patients with cancer in the South East London Cancer Network – an area of 1.7 million residents in the boroughs of Lambeth, Southwark, Lewisham, Bexley, Bromley and Greenwich.